复合式频率跟踪控制电路的设计

Design of complex frequency tracking control circuit

针对加热电源中传统模拟频率跟踪控制电路频率跟踪范围小、锁相时间长,而数字频率跟踪控制电路硬件成本高、程序复杂不易实现等问题,提出了一种由S3F9454单片机、CD4046和SG3525组成的数字模拟复合频率跟踪控制电路.仿真及实验结果表明,当电路中电流频率达到30 k Hz以上时,通过软件的快速排序算法,将单片机从SG3525采集到的电流、电压频率的反馈差值实现快速排序,高效实现频率跟踪.运用复合式频率跟踪控制方法能够实现对频率快速准确的跟踪,频率跟踪范围广,对不同负载适应能力强.

Aiming at the problems of heating power supply that the trace range of traditional analog frequency tracking control circuit frequency is small, the hardware costs of digital frequency tracking control circuit frequency is high and the complex procedures are not easy to implement, etc., this paper proposed a digital and analog composite frequency tracking control circuit, which takes S3F9454 CD4046 and SG3525 as its main components. The simulation and experimental results validate the proposed circuit when the current frequency of the circuit reaches 30 KHZ high and above. Through software quicksort algorithm, the MCU quick sorts the current and voltage frequency difference of feedback from SG3525, and realizes the efficient frequency tracking. Using the compound frequency tracking control method can achieve fast and accurate frequency tracking, adaptable to different loads, wide frequency tracking range, low hardware cost, simple structure and easy to implement.